8GB RAM upgrade for Late 2008 Macbook, Aluminum Unibody, Voltage??

I am looking to upgrade the RAM memory in my late 2008 Macbook aluminum unibody, 2.0 GHz (Model Identifier: Macbook 5,1) and wanted to know the difference between a 1.35 Volt and a 1.5 Volt stick? Is one safer for my model than the other? The choice of 2 brands is the Crucial and the OWC 8BG RAM sticks:

OWC: DDR3 SDRAM, 204 PIN, DDR3-1066, PC3-8500, 1.5V

Crucial: DDR3 PC3-8500, DDR3-1066, 512Meg x 64, 1.35V

Is there a major difference between these 2 and which is the best choice?

Any help is greatly appreciated!! Thanks!